Solar can provide key grid services: California ISO report

In a finding that could affect the outlook for renewables integration, solar facilities with smart inverter technology can provide key grid services at levels that are similar to, and in some cases better than, conventional power plants, according to a study by California’s grid operator, the Department of Energy’s National Renewable Energy Laboratory and First Solar.

“These findings mean renewable energy in the [California Independent System Operator] footprint — and beyond — could be integrated into power grids at a much higher level and faster pace than once believed,” Clyde Loutan, ISO’s senior adviser for renewable energy integration, said Wednesday.

The study comes amid concerns about how growing amounts of renewable generation will affect grid operations. The US has 25,000 MW of utility-scale photovoltaic capacity, plus 1,800 MW of concentrating solar, according to the report, titled “Using Renewables to Operate a Low-carbon Grid.”

California is at the forefront in the shifting generation mix, with renewable requirements that climb to 50% by 2030. The ISO has more than 9,000 MW of grid-connected solar and expects rooftop solar to grow from about 5,000 MW to 9,000 MW by 2020. Also, the grid operator estimates an extra 20,000 MW of renewables may be needed to meet the state’s renewable portfolio standard.

The ISO is being forced to curtail renewables during periods of growing oversupply, according to the report. The grid operator curtailed 2,000 MW of renewables on one day in April, it said.

“With increased frequency of curtailment, more opportunity is created if the industry can tap into the controllability of the renewable resources, and thus expand the carbon-free resources for such services,” the report said.